ML20070E385

Forwards Addl Info Re Proposed Change in Instrument Surveillance Requirement Test Frequency of Tables 4.3-1 & 4.3-2 & Thermal/Hydraulic Design Parameters for Unit 1 Reload Safety Evaluation

ML20070E385
Person / Time
Site:	Sequoyah
Issue date:	12/13/1982
From:	Mills L TENNESSEE VALLEY AUTHORITY
To:	Adensam E Office of Nuclear Reactor Regulation
References
NUDOCS 8212170236
Download: ML20070E385 (6)

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4 TENNESSEE VALLEY AUTHORITY CH ATTANOOGA. TENNESSEE 37401 400 Chestnut Street Tower II Decembe r 13, 1982 Director of Nuclear Reactor Regulation Attention:

Ms. E. Adensam, Chief Licensing Branch No. 4 Division of Licensing U.S. Nuclear Regulatory Commission Washington, D.C.

20555

Dear Ms. Adensam:

In the M::tter of

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Docket Nos. 50-327 Tennessee Valley Authority

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50-323 As requested by Melanie Miller of your staff, we are providing a response to a NBC verbal question and request for additional information. Enclosure 1 provides the rasponse to the questions concerning change No. 3 of TVA-SQN-TS-36, Proposed Change in the Instrumentation Surveillance Requirement Test Frequency of Tables 4.3-1 and 4.3-2. provides additional information regarding the thermal / hydraulic design parameters for the Sequoyah unit 1 Reload Safety Evaluation (TVA-SQN-TS-37).

If you have any questions concerning this matter, please get in touch with J. E. Wills at FTS 858-2683 Very truly yours, TENNESSEE VALLEY AUTHORITY L. M. Mills, M nager Nuclear Licensing Sworn o nd subscribed before me t s day oft d4/1982 W

L' Notary Public My Commission Expires

--b Enclosures cc:

U.S. Nuclear Regulatory Commission (Enclosures)

Region II Attn:

Mr. James P. O'Reilly, Regional Administrator 101 Marietta Street, Suite 3100 Atlanta, Georgia 30303 P212170236 821213 D

PDR ADOCK 05000327 P

PDR An Equal Opportunity Employer

ENCLOSURE 1 RESPONSE TO NRC QUESTION CONCERNING CHANGE NO. 3 0F IVA-SQN-TS-36 Proposed Technical Specification Change in the Instrumentation Surveillance Requirement Test Frequency of Tables 4.3-1 and 4.3-2 SEQUOYAH NUCLEAR PLANT UNITS 1/2 e

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i E9 CLOSURE 1 i

NRC Question:

Did TVA evaluate the calibration data f or trends?

TVA_ Response:

Recalibration of the SSPS bistables at Sequoyah.is not performed unless the setpoint has drifted more than 50 percent of the tolerance value. The tolerance values are specified to be +.5 percent of the instrument span.

The drif t allowed by technical specifications, defined as the difference between the trip setpoint and the allowable value, is 11 percent.

Review of plant functional test data packages indicated that only a small f raction of the bistables tested even exceeded the +.25 percent recalibration criteria. None exceeded the specified tolerance or tech spec values. The data shows the bistables to be extremely stable. Drift, where measured, was random in nature and no drif t pattern (high or low) was indicated.

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ENCLOSURE 2 RESPONSE TO NRC RFAUEST FOR ADDITIONAL INFORMATION, IVA-SQN-IS-37, 'IIIERNAL AND HYDRAULIC DESIGN PARAMEIERS FOR RELOAD SAFETY EVALUATION SEQUOYAH NUCLEAR PLANT UNIT I g

BNCLOSURE 3 THERMAL / HYDRAULIC TABLE OF DESIGN PARAMETERS A.

Performance Characteristics 1.

Total Core Heat Output (NW t) 3411.

2.

System Pressure (psia) - nominal 2250.

- minimum st eady. state 2200.

B.

Coolant Flow 1.

Thermal Design Flow - (1bs/hr) 13 8.0 x 105

- (GPMT) 365600.

2.

Core Flow (w/Bypats)- (Ibs/hr) 127.7 x 105 (GPMT) 338180.

3.

Pressure Drop Across Core (psi) 23.4 1 2.3 4.

Average Mass Velocity (1bs/hr/f t8) 2.50 x 10*

C.

Coolant _ Temperature 1.

Design Inlet Temperature ('F) 546.7 2.

Core Average KI (*F) 67.6 D.

Heat Transfer Characteristics 1.

Core Flow Area (FT2) 51.1 2.

Core Average Heat Flux (BTU /Hr/FT8) 189800.

3.

Average Linear Heat Rate (KW/FT) 5.44 4.

Maximum Linear Heat Rate (EW/FT) 12.6*

I 4a. Peak Linear Power f or Determination of 18.0 Protection Setpoints (EW/FT) (Table 4.4-1) 5.

Minimum DNBR at Nominal Conditions

- Typical Cell 2.22

- Thimble (w/ cold wall) cell 1.81 6.

Minimum DNBR for Design and Anticipated Transients >1.30 (Figures of FS AR, Section 15.2, provide plots of DNBR)

• This value is a ssociated with an F value of 2.32.

q Note:

These values. are being provided because there are rot any significant differences between cycle 1 and cycle 2.

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Latest Value of Measured Core Flow 38.3763 x 104 gym 144.8501 x 105 lbs/hr Reference to F B Annroval F H has been approved for the Trojan applications, docket Nos. 50-344, and A

is included in their tech specs.

Previous approval of F,'J use was granted by the August 13, 1982 letter from Charles Trammel, Werating Reactors Branch No. 3 (NRC) to Bart Withers, Portland General Electric.

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